diff --git a/BUGS b/BUGS
index 3cc7839..02590c4 100644
--- a/BUGS
+++ b/BUGS
@@ -89,3 +89,132 @@ Known problems or mis-features:
     * There is some places in the source with obscure variable names
       and not much in the way of comments.  We need some major cleanup
       and documentation.
+
+    * On a Dec Alpha, make check for version 2.11.0t1 core dumps:
+
+	From vandermj@molbio.sbphrd.com  Fri Sep 24 06:15:28 1999
+	Subject: Re: calc version 2.11.0t1
+	Date: Fri, 24 Sep 1999 09:15:02 -0400
+
+	It dies as follows:
+
+	...
+	1802: a = surd(2,3)
+	1803: a == surd(2,3)
+	1804: surd_value(a) == 2+3i
+	Segmentation fault
+
+	dbx shows:
+	signal Segmentation fault at   [objcall:155 +0xc,0x1200507b4]   index = oap->actions[action];
+	(dbx) where
+	>  0 objcall(action = 14, v1 = 0x1400203d0, v2 = 0x1400203e0, v3 = (nil)) ["obj.c":155, 0x1200507b4]
+	   1 comparevalue(v1 = 0x1400203d0, v2 = 0x1400203e0) ["value.c":2329, 0x12007f250]
+	   2 o_eq() ["opcodes.c":2659, 0x12003728c]
+	   3 calculate(fp = 0x14007fce0) ["opcodes.c":3614, 0x12003942c]
+	   4 o_usercall(fp = 0x14007fce0, index = 39, argcount = 0) ["opcodes.c":2602, 0x120037080]
+	   5 calculate(fp = 0x14003bfa0) ["opcodes.c":3622, 0x120039488]
+	   6 evaluate(nestflag = 14) ["codegen.c":210, 0x120028768]
+	   7 getcommands(toplevel = 536864560) ["codegen.c":158, 0x1200285bc]
+	   8 getcommands(toplevel = 536864560) ["codegen.c":122, 0x1200284dc]
+	   9 main() ["calc.c":279, 0x12001f61c]
+
+	However On 25-Sep-99  9:18, Ernest Bowen wrote:
+
+	    Last night I downloaded 2.11.0t1 and without changing Makefile
+	    or anything else did a make and make check.  Absolutely no
+	    reported errors or warnings and the check "passed all tests".
+	    The machine I'm using is a Dec 20 alpha running Digitial
+	    UNIX V4.0B (Rev 564).
+
+	Any ideas on how to reconcile these different results?
+
+    * On Sun SPARCstation running Solaris 2.5.1 compiling with
+      cc version 4.0 with -Xc option 'make check' fails on the hash
+      functions.  However when compiled with gcc everything seems to
+      work just fine.
+
+	From: "Dr.D.J.Picton" <dave@aps5.ph.bham.ac.uk>
+	Date: Fri, 8 May 1998 10:54:43 +0100
+
+	Platform: Sun SPARCstation
+
+	Operating system: Solaris 2.5.1
+
+	Compiler: cc version 4.0 with -Xc option.
+
+	The code compiled OK but the sha() and sha1() functions give errors with
+	make check.   These functions clearly are broken.  For example,
+	sha(sha()) gives
+
+	0xea19f96cdd568ad1084a17acc6103d92c0ef7708   not
+	0xf96cea198ad1dd5617ac084a3d92c6107708c0ef
+
+	Interestingly, the consistency checks work OK e.g.
+	>B = blk() = {"a", "b", "c"};
+	>sha(B) == sha("abc");
+		1
+
+	**** Non-true result (0): 7108: sha(sha()) ==
+	0xf96cea198ad1dd5617ac084a3d92c6107708c0ef
+	**** Non-true result (0): 7109:
+	sha(sha("a"))==0x37f297772fae4cb1ba39b6cf9cf0381180bd62f2
+	**** Non-true result (0): 7110:
+	sha(sha("ab"))==0x488373d362684af3d3f7a6a408b59dfe85419e09
+	**** Non-true result (0): 7111:
+	sha(sha("abc"))==0x0164b8a914cd2a5e74c4f7ff082c4d97f1edf880
+	**** Non-true result (0): 7112:
+	sha(sha("abcd"))==0x082c73b06f71185d840fb4b28eb3abade67714bc
+	**** Non-true result (0): 7113:
+	sha(sha("abcde"))==0xd624e34951bb800f0acae773001df8cffe781ba8
+	**** Non-true result (0): 7114:
+	sha(sha("abcdef"))==0x2a589f7750598dc0ea0a608719e04327f609279a
+	**** Non-true result (0): 7115:
+	sha(sha("abcdefg"))==0x5bdf01f9298e9d19d3f8d15520fd74eed600b497
+	**** Non-true result (0): 7116:
+	sha(sha("abcdefgh"))==0x734ba8b31975d0dbae4d6e249f4e8da270796c94
+	**** Non-true result (0): 7117: sha(sha(1)) ==
+	0x864c8d09e828c7c31d62693736a5a9302c282777
+	**** Non-true result (0): 7118: sha(sha(2)) ==
+	0x2c0b59c512cb20fad6bb0883b69c9f5a46545808
+	**** Non-true result (0): 7119:
+	sha(sha(22/7)==0x7ddb7f8a7e9d70757f157744fddea7a6c6a6bcc6
+	**** Non-true result (0): 7120:
+	sha(sha(isqrt(2e1000)==0x6db8d9cf0b018b8f9cbbf5aa1edb8066d19e1bb0
+	7121: sha("x", "y", "z") == sha("xyz")
+	**** Non-true result (0): 7122: sha(sha("this is", 7^19-8, ..., "hash")) ==
+	0x21e4...
+	7123: z = sha(list(1,2,3), "curds and whey", 2^21701-1, pi());
+	**** Non-true result (0): 7124: sha(z) ==
+	0x36dcca3e51865c30a2cf738023cda446f1368340
+
+	**** Non-true result (0): 7207: sha1(sha1()) ==
+	0xda39a3ee5e6b4b0d3255bfef95601890afd80709
+	7208: sha1("x", "y", "z") == sha1("xyz")
+	**** Non-true result (0): 7209: sha1(sha1("this is",7^19-8,"a
+	composit",3i+4.5,"hash")) == ...
+	7210: z = sha1(list(1,2,3), "curds and whey", 2^21701-1, pi());
+	**** Non-true result (0): 7211: sha1(z) ==
+	0xc19e7317675dbf71e293b4c41e117169e9da5b6f
+
+	**** Non-true result (0): 7217:
+	sha1(sha1("a"))==0x86f7e437faa5a7fce15d1ddcb9eaeaea377667b8
+	**** Non-true result (0): 7218:
+	sha1(sha1("ab"))==0xda23614e02469a0d7c7bd1bdab5c9c474b1904dc
+	**** Non-true result (0): 7219:
+	sha1(sha1("abc"))==0xa9993e364706816aba3e25717850c26c9cd0d89d
+	**** Non-true result (0): 7220:
+	sha1(sha1("abcd"))==0x81fe8bfe87576c3ecb22426f8e57847382917acf
+	**** Non-true result (0): 7221:
+	sha1(sha1("abcde"))==0x03de6c570bfe24bfc328ccd7ca46b76eadaf4334
+	**** Non-true result (0): 7222:
+	sha1(sha1("abcdef"))==0x1f8ac10f23c5b5bc1167bda84b833e5c057a77d2
+	**** Non-true result (0): 7223:
+	sha1(sha1("abcdefg"))==0x2fb5e13419fc89246865e7a324f476ec624e8740
+	**** Non-true result (0): 7224:
+	sha1(sha1("abcdefgh"))==0x425af12a0743502b322e93a015bcf868e324d56a
+	**** Non-true result (0): 7225:
+	sha1(sha1(1))==0x53dd4e1734ad47d45e41c23e4ce42d7f1f98c1e8
+	**** Non-true result (0): 7226:
+	sha1(sha1(22/7))==0xf8e2510f85f7b9bf088b321188e9f70620f44246
+	**** Non-true result (0): 7227:
+	sha1(sha1(isqrt(2e1000)))==0x6852a1365c51050c3d039e3c5d9cf29c12283ef4
diff --git a/CHANGES b/CHANGES
index fab8e50..05aa939 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,7 +1,5 @@
 Following is the change from calc version 2.11.0t1 to date:
 
-    Fixed BSDI compile problems related to sys_errlist.
-
     Removed the makefile symbol MAIN.  Now forcing all funcions to correctly
     be reclared main.  To passify some old broken compilers, a return 0;
     (instead of an exit(0);) is used at the end of main().
@@ -12,6 +10,17 @@ Following is the change from calc version 2.11.0t1 to date:
 
     Fixed misc compile warnings.
 
+    Added the program calc_errno.c and the Makefile symbol ERRNO_DECL.
+    If ERRNO_DECL is empty, calc_errno.c will try various ways to
+    declare errno, sys_errlist and sys_nerr.  On success or when
+    it gives up, calc_errno will output the middle of the calc_errno.h
+    header file.  If ERRNO_DECL is  -DERRNO_NO_DECL, or -DERRNO_STD_DECL
+    or -DERRNO_OLD_DECL then the Makefile will build the middle
+    of the calc_errno.h header file without calc_errno.c's help.
+
+    The func.c file now includes the constructed header file calc_errno.h
+    to ensure that errno, sys_errlist and sys_nerr are declared correctly.
+
 
 Following is the change from calc version 2.10.3t5.38 to 2.11.0t0:
 
diff --git a/Makefile b/Makefile
index fd480df..647d1eb 100644
--- a/Makefile
+++ b/Makefile
@@ -206,6 +206,39 @@ HAVE_MEMMOVE=
 ALIGN32= -DMUST_ALIGN32
 #ALIGN32= -UMUST_ALIGN32
 
+# On most machines: errno sys_errlist and sys_nerr are declared
+# by either <stdio.h> and/or <errno.h>.  But some systems declare
+# them somewhere else or do not declare them at all!
+#
+# If the system were doing a proper job in headers, this should declare them:
+#
+#	#include <stdio.h>
+#	#include <errno.h>
+#
+# But one some systems one must explicitly declare them as:
+#
+#	extern int errno;
+#	extern const char *const sys_errlist[];
+#	extern int sys_nerr;
+#
+# and on some old systems they must be explicitly and incorrectly declared as:
+#
+#	extern int errno;
+#	extern char *sys_errlist[];
+#	extern int sys_nerr;
+#
+# ERRNO_DECL=			let calc_errno.c determine how to declare them
+# ERRNO_DECL= -DERRNO_NO_DECL	headers declare them correctly
+# ERRNO_DECL= -DERRNO_STD_DECL	one must explicitly declare then
+# ERRNO_DECL= -DERRNO_OLD_DECL	one must explicitly & incorrectly declare them
+#
+# When in doubt, be safe leave ERRNO_DECL empty.
+#
+ERRNO_DECL=
+#ERRNO_DECL= -DERRNO_NO_DECL
+#ERRNO_DECL= -DERRNO_STD_DECL
+#ERRNO_DECL= -DERRNO_OLD_DECL
+
 # where to install binary files
 #
 BINDIR= /usr/local/bin
@@ -622,29 +655,6 @@ ALLOW_CUSTOM= -DCUSTOM
 #
 ###
 #
-# BSDI's BSD/OS 2.0 (or later) set
-#
-# for better performance, set the following above:
-#     DEBUG= -O2
-#
-#CCWARN= -Wall -Wno-implicit -Wno-comment
-#CCOPT= ${DEBUG} ${NO_SHARED}
-#CCMISC= -ansi
-#
-#CFLAGS= ${CCWARN} ${CCOPT} ${CCMISC}
-#ICFLAGS= ${CCWARN} ${CCMISC}
-#
-#CCMAIN= ${ICFLAGS}
-#CCSHS= ${CFLAGS}
-#
-#LCFLAGS=
-#LDFLAGS= ${NO_SHARED} ${LD_NO_SHARED}
-#ILDFLAGS=
-#
-#CC= ${PURIFY} shlicc2
-#
-###
-#
 # Solaris 2.x Sun cc compiler
 #
 # for better performance, set the following above:
@@ -668,7 +678,7 @@ ALLOW_CUSTOM= -DCUSTOM
 #
 ###
 #
-# Red Hat Linux 6.0
+# Red Hat Linux 6.0 and BSDI's BSD/OS 4.0 (or later) set
 #
 # for better performance, set the following above:
 #     DEBUG= -O2
@@ -798,7 +808,7 @@ BUILD_H_SRC= align32.h args.h calcerr.h conf.h endian_calc.h \
 	fposval.h have_const.h have_fpos.h have_malloc.h \
 	have_memmv.h have_newstr.h have_offscl.h have_posscl.h \
 	have_stdlib.h have_string.h have_times.h have_uid_t.h \
-	have_unistd.h longbits.h longlong.h terminal.h
+	have_unistd.h longbits.h longlong.h terminal.h calc_errno.h
 
 # we build these .c files during the make
 #
@@ -810,7 +820,7 @@ BUILD_C_SRC= calcerr.c
 #
 UTIL_C_SRC= align32.c endian.c longbits.c have_newstr.c have_uid_t.c \
 	have_const.c have_stdvs.c have_varvs.c fposval.c have_fpos.c \
-	longlong.c have_offscl.c have_posscl.c have_memmv.c
+	longlong.c have_offscl.c have_posscl.c have_memmv.c calc_errno.c
 
 # these awk and sed tools are used in the process of building BUILD_H_SRC
 # and BUILD_C_SRC
@@ -824,16 +834,17 @@ UTIL_MISC_SRC= calcerr_h.sed calcerr_h.awk calcerr_c.sed calcerr_c.awk \
 #
 UTIL_OBJS= endian.o longbits.o have_newstr.o have_uid_t.o \
 	have_const.o fposval.o have_fpos.o longlong.o try_strarg.o \
-	have_stdvs.o have_varvs.o have_posscl.o have_memmv.o
+	have_stdvs.o have_varvs.o have_posscl.o have_memmv.o calc_errno.o
 
 # these temp files may be created  (and removed) during the build of BUILD_C_SRC
 #
-UTIL_TMP= ll_tmp fpos_tmp fposv_tmp const_tmp uid_tmp newstr_tmp vs_tmp
+UTIL_TMP= ll_tmp fpos_tmp fposv_tmp const_tmp uid_tmp newstr_tmp vs_tmp \
+	calc_errno_tmp
 
 # these utility progs may be used in the process of building BUILD_H_SRC
 #
 UTIL_PROGS= align32 fposval have_uid_t longlong have_const \
-	endian longbits have_newstr have_stdvs have_varvs
+	endian longbits have_newstr have_stdvs have_varvs calc_errno
 
 # These files are required by the regress.cal regression test.
 #
@@ -1804,6 +1815,98 @@ args.h: have_stdvs.c have_varvs.c have_string.h have_unistd.h have_string.h
 	    true; \
 	fi
 
+calc_errno.h: calc_errno.c ${MAKE_FILE}
+	-${Q}rm -f calc_errno.h calc_errno calc_errno_tmp
+	${Q}echo 'forming calc_errno.h'
+	${Q}echo '/*' > calc_errno.h
+	${Q}echo ' * DO NOT EDIT -- generated by the Makefile' >> calc_errno.h
+	${Q}echo ' */' >> calc_errno.h
+	${Q}echo '' >> calc_errno.h
+	${Q}echo '' >> calc_errno.h
+	${Q}echo '#if !defined(__CALC_ERRNO_H__)' >> calc_errno.h
+	${Q}echo '#define __CALC_ERRNO_H__' >> calc_errno.h
+	${Q}echo '' >> calc_errno.h
+	${Q}echo '' >> calc_errno.h
+	-${Q}if [ X"${ERRNO_DECL}" = X"-DERRNO_NO_DECL" ]; then \
+	    echo '/*' >> calc_errno.h; \
+	    echo ' * The calc Makefile explicitly told us' >> calc_errno.h; \
+	    echo ' * how to declare errno and friends.' >> calc_errno.h; \
+	    echo ' */' >> calc_errno.h; \
+	    echo '' >> calc_errno.h; \
+	    echo '#include <stdio.h>' >> calc_errno.h; \
+	    echo '#include <errno.h>' >> calc_errno.h; \
+	elif [ X"${ERRNO_DECL}" = X"-DERRNO_STD_DECL" ]; then \
+	    echo '/*' >> calc_errno.h; \
+	    echo ' * The calc Makefile explicitly told us' >> calc_errno.h; \
+	    echo ' * how to declare errno and friends.' >> calc_errno.h; \
+	    echo ' */' >> calc_errno.h; \
+	    echo '' >> calc_errno.h; \
+	    echo 'extern int errno;			' \
+		 '/* last system error */' >> calc_errno.h; \
+	    echo 'extern const char *const sys_errlist[];' \
+		 ' /* system error messages*/' >> calc_errno.h; \
+	    echo 'extern int sys_nerr;			' \
+		 '/* number of system errors */' >> calc_errno.h; \
+	elif [ X"${ERRNO_DECL}" = X"-DERRNO_OLD_DECL" ]; then \
+	    echo '/*' >> calc_errno.h; \
+	    echo ' * The calc Makefile explicitly told us' >> calc_errno.h; \
+	    echo ' * how to declare errno and friends.' >> calc_errno.h; \
+	    echo ' */' >> calc_errno.h; \
+	    echo '' >> calc_errno.h; \
+	    echo 'extern int errno;		' \
+		 '/* last system error */' >> calc_errno.h; \
+	    echo 'extern char *sys_errlist[];' \
+		 '	 /* system error messages*/' >> calc_errno.h; \
+	    echo 'extern int sys_nerr;		' \
+		 '/* number of system errors */' >> calc_errno.h; \
+	else \
+	    ${CC} ${CCMAIN} -DTRY_ERRNO_NO_DECL \
+		  calc_errno.c -o calc_errno 2>calc_errno_tmp; \
+	    if [ -x ./calc_errno ]; then \
+		./calc_errno >> calc_errno.h; \
+	    else \
+		${CC} ${CCMAIN} -DTRY_ERRNO_STD_DECL \
+		      calc_errno.c -o calc_errno 2>calc_errno_tmp; \
+		if [ -x ./calc_errno ]; then \
+		    ./calc_errno >> calc_errno.h; \
+		else \
+		    ${CC} ${CCMAIN} -DTRY_ERRNO_OLD_DECL \
+			  calc_errno.c -o calc_errno 2>calc_errno_tmp; \
+		    if [ -x ./calc_errno ]; then \
+			./calc_errno >> calc_errno.h; \
+		    else \
+	    echo '/*' >> calc_errno.h; \
+	    echo ' * We were unable to to determine' >> calc_errno.h; \
+	    echo ' * how to declare errno and friends.' >> calc_errno.h; \
+	    echo ' * So we will guess this will work' >> calc_errno.h; \
+	    echo ' * and hope for the best.' >> calc_errno.h; \
+	    echo ' */' >> calc_errno.h; \
+	    echo '' >> calc_errno.h; \
+	    echo 'extern int errno;			' \
+		 '/* last system error */' >> calc_errno.h; \
+	    echo 'extern const char *const sys_errlist[];' \
+		 ' /* system error messages*/' >> calc_errno.h; \
+	    echo 'extern int sys_nerr;			' \
+		 '/* number of system errors */' >> calc_errno.h; \
+		    fi; \
+		fi; \
+	    fi; \
+	fi
+	${Q}echo '' >> calc_errno.h
+	${Q}echo '' >> calc_errno.h
+	${Q}echo '#endif /* !__CALC_ERRNO_H__ */' >> calc_errno.h
+	-${Q}rm -f calc_errno calc_errno_tmp
+	${Q}echo 'calc_errno.h formed'
+	-@if [ -z "${Q}" ]; then \
+	    echo ''; \
+	    echo '=-=-= start of $@ =-=-='; \
+	    cat $@; \
+	    echo '=-=-= end of $@ =-=-='; \
+	    echo ''; \
+	else \
+	    true; \
+	fi
+
 calcerr.h: calcerr.tbl calcerr_h.sed calcerr_h.awk ${MAKE_FILE}
 	-${Q}rm -f calerr.h
 	${Q}echo 'forming calcerr.h'
@@ -2190,6 +2293,7 @@ env:
 	@echo "HAVE_UID_T=${HAVE_UID_T}"; echo ""
 	@echo "HAVE_NEWSTR=${HAVE_NEWSTR}"; echo ""
 	@echo "ALIGN32=${ALIGN32}"; echo ""
+	@echo "ERRNO_DECL=${ERRNO_DECL}"; echo ""
 	@echo "BINDIR=${BINDIR}"; echo ""
 	@echo "TOPDIR=${TOPDIR}"; echo ""
 	@echo "LIBDIR=${LIBDIR}"; echo ""
diff --git a/calc_errno.c b/calc_errno.c
new file mode 100644
index 0000000..6114840
--- /dev/null
+++ b/calc_errno.c
@@ -0,0 +1,123 @@
+/*
+ * errno - Determine how to declare errno, sys_errlist and sys_nerr
+ *
+ * On most machines: errno sys_errlist and sys_nerr are declared
+ * by either <stdio.h> and/or <errno.h>.  But some systems declare
+ * them somewhere else or do not declare them at all!
+ *
+ * If the system were doing a proper job in headers, this should declare them:
+ *
+ *	#include <stdio.h>
+ *	#include <errno.h>
+ *
+ * But one some systems one must explicitly declare them as:
+ *
+ *	extern int errno;
+ *	extern const char *const sys_errlist[];
+ *	extern int sys_nerr;
+ *
+ * and on some old systems they must be explicitly and incorrectly declared as:
+ *
+ *	extern int errno;
+ *	extern char *sys_errlist[];
+ *	extern int sys_nerr;
+ *
+ * The purpose of this utility is try and find the right way to declare
+ * them and to output the middle of a header file called calc_errno.h.
+ */
+
+/*
+ * Copyright (c) 1999 by Landon Curt Noll.  All Rights Reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose and without fee is hereby granted,
+ * provided that the above copyright, this permission notice and text
+ * this comment, and the disclaimer below appear in all of the following:
+ *
+ *	supporting documentation
+ *	source copies
+ *	source works derived from this source
+ *	binaries derived from this source or from derived source
+ *
+ * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+ * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ *
+ * chongo was here	/\../\
+ */
+
+#include <stdio.h>
+#if defined(TRY_ERRNO_NO_DECL)
+#  include <errno.h>
+#endif /* TRY_ERRNO_NO_DECL */
+
+int
+main(void)
+{
+
+#if defined(TRY_ERRNO_NO_DECL)
+	printf("/*\n");
+	printf(" * The following comments were produced by calc_errno\n");
+	printf(" * in an effort to see if these values were correctly\n");
+	printf(" * declared when calc_errno.c was compiled.\n");
+	printf(" */\n\n");
+	printf("/* Initially errno is %d */\n", errno);
+	printf("/* There are %d entries in sys_errlist[] */\n", sys_nerr);
+	printf("/* The 2nd sys_errlist entry is \"%s\" */\n\n", sys_errlist[1]);
+	printf("/*\n");
+	printf(" * Based on the above, calc_errno now knows\n");
+	printf(" * how to declare errno and friends.\n");
+	printf(" */\n\n");
+	printf("#include <stdio.h>\n");
+	printf("#include <errno.h>\n");
+#elif defined(TRY_ERRNO_OLD_DECL)
+	extern int errno;		/* last system error */
+	extern char *sys_errlist[];	/* system error messages */
+	extern int sys_nerr;		/* number of system errors*/
+
+	printf("/*\n");
+	printf(" * The following comments were produced by calc_errno\n");
+	printf(" * in an effort to see if these values were correctly\n");
+	printf(" * declared when calc_errno.c was compiled.\n");
+	printf(" */\n\n");
+	printf("/* Initially errno is %d */\n", errno);
+	printf("/* There are %d entries in sys_errlist[] */\n", sys_nerr);
+	printf("/* The 2nd sys_errlist entry is \"%s\" */\n\n", sys_errlist[1]);
+	printf("/*\n");
+	printf(" * Based on the above, calc_errno now knows\n");
+	printf(" * how to declare errno and friends.\n");
+	printf(" */\n\n");
+	printf("extern int errno;\t\t/* last system error */\n");
+	printf("extern char *sys_errlist[];\t"
+	       "/* system error messages */\n");
+	printf("extern int sys_nerr;\t\t/* number of system errors*/\n");
+#else	/* assume defined(TRY_ERRNO_STD_DECL) */
+	extern int errno;			/* last system error */
+	extern const char *const sys_errlist[];	/* system error messages */
+	extern int sys_nerr;			/* number of system errors*/
+
+	printf("/*\n");
+	printf(" * The following comments were produced by calc_errno\n");
+	printf(" * in an effort to see if these values were correctly\n");
+	printf(" * declared when calc_errno.c was compiled.\n");
+	printf(" */\n\n");
+	printf("/* Initially errno is %d */\n", errno);
+	printf("/* There are %d entries in sys_errlist[] */\n", sys_nerr);
+	printf("/* The 2nd sys_errlist entry is \"%s\" */\n\n", sys_errlist[1]);
+	printf("/*\n");
+	printf(" * Based on the above, calc_errno now knows\n");
+	printf(" * how to declare errno and friends.\n");
+	printf(" */\n\n");
+	printf("extern int errno;\t\t\t/* last system error */\n");
+	printf("extern const char *const sys_errlist[];\t"
+	       "/* system error messages */\n");
+	printf("extern int sys_nerr;\t\t\t/* number of system errors*/\n");
+#endif
+
+	/* exit(0); */
+	return 0;
+}
diff --git a/file.c b/file.c
index 5d67944..f039a51 100644
--- a/file.c
+++ b/file.c
@@ -1141,6 +1141,7 @@ rewindall(void)
  *
  * NOTE: Does not support negative file positions.
  */
+/*ARGSUSED*/
 static ZVALUE
 filepos2z(FILEPOS pos)
 {
@@ -1493,6 +1494,7 @@ setloc(FILEID id, ZVALUE zpos)
  * returns:
  *	file size as a ZVALUE
  */
+/*ARGSUSED*/
 static ZVALUE
 off_t2z(off_t siz)
 {
@@ -1555,6 +1557,7 @@ dev2z(dev_t dev)
  * returns:
  *	file size as a ZVALUE
  */
+/*ARGSUSED*/
 static ZVALUE
 inode2z(ino_t inode)
 {
@@ -1841,7 +1844,8 @@ getscanfield(FILE *fp, BOOL skip, unsigned int width, int scannum, char *scanptr
 			if (c == EOF || c == '\0')
 				break;
 			chnum++;
-			if(scannum && (memchr(scanptr,c,scannum)==NULL) ^ comp)
+			if(scannum &&
+			   ((memchr(scanptr,c,scannum)==NULL) ^ comp))
 				break;
 			if (!skip) {
 				*b++ = c;
@@ -1918,7 +1922,7 @@ getscanwhite(FILE *fp, BOOL skip, unsigned int width, int scannum, char **strptr
 			if (c == EOF || c == '\0')
 				break;
 			chnum++;
-			if(scannum && !isspace(c) ^ comp)
+			if(scannum && (!isspace(c) ^ comp))
 				break;
 			if (!skip) {
 				*b++ = c;
diff --git a/func.c b/func.c
index ce8afda..f074dd6 100644
--- a/func.c
+++ b/func.c
@@ -10,15 +10,15 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <sys/types.h>
-#include <errno.h>
 
 #if defined(FUNCLIST)
 
-#include <stdio.h>
 #define CONST /* disabled for FUNCLIST in case NATIVE_CC doesn't have it */
 
 #else /* FUNCLIST */
 
+#include "calc_errno.h"
+
 #include "have_unistd.h"
 #if defined(HAVE_UNISTD_H)
 #include <unistd.h>
diff --git a/lib_util.c b/lib_util.c
index 10e2706..183cfd1 100644
--- a/lib_util.c
+++ b/lib_util.c
@@ -241,8 +241,8 @@ convhex2z(char *hex)
 		/* slen is even now */
 
 		/* eat two hex chars at a time until the HALF is full */
-		for (; (slen % (BASEB/4)) != 0; slen -= 2) {
-			*hp = ((*hp<<8) | hex2bin(*sp++, *sp++));
+		for (; (slen % (BASEB/4)) != 0; slen -= 2, sp += 2) {
+			*hp = ((*hp<<8) | hex2bin(sp[0], sp[1]));
 		}
 
 		/* move on to the next HALF */
diff --git a/qfunc.c b/qfunc.c
index 17faadb..e9d8f30 100644
--- a/qfunc.c
+++ b/qfunc.c
@@ -1284,7 +1284,7 @@ qcfsim(NUMBER *q, long rnd)
 	zmodinv(q->num, q->den, &den1);
 	if (s >= 0) {
 		zsub(q->den, den1, &den2);
-		if (s > 0 || ((zrel(den1, den2) < 0) ^ !(rnd & 16))) {
+		if (s > 0 || ((zrel(den1, den2) < 0) ^ (!(rnd & 16)))) {
 			zfree(den1);
 			res->den = den2;
 			zmul(den2, q->num, &tmp1);
diff --git a/version.c b/version.c
index 681021c..b22de37 100644
--- a/version.c
+++ b/version.c
@@ -12,7 +12,7 @@
 #define MAJOR_VER	2	/* major version */
 #define MINOR_VER	11	/* minor version */
 #define MAJOR_PATCH	0	/* patch level or 0 if no patch */
-#define MINOR_PATCH	"1"	/* test number or empty string if no patch */
+#define MINOR_PATCH	"2"	/* test number or empty string if no patch */
 
 /*
  * calc version constants
diff --git a/zfunc.c b/zfunc.c
index 776f2ef..44b7f37 100644
--- a/zfunc.c
+++ b/zfunc.c
@@ -1522,7 +1522,7 @@ zsqrt(ZVALUE z, ZVALUE *dest, long rnd)
 	u = (HALF)(s ? BASE1 : 0);
 	if (k < BASEB) {
 		A[m1 - 1] = (HALF)(e >> (BASEB - 1));
-		A[m1 - 2] = (HALF)(e << 1 | (s > 0));
+		A[m1 - 2] = ((HALF)(e << 1) | (HALF)(s > 0));
 		A[m1 - 3] = (HALF)(f >> BASEB);
 		A[m1 - 4] = (HALF)f;
 		m = m1 - 2;
@@ -1531,7 +1531,7 @@ zsqrt(ZVALUE z, ZVALUE *dest, long rnd)
 	else {
 		A[m1 - 1] = 1;
 		A[m1 - 2] = (HALF)(e >> (BASEB - 1));
-		A[m1 - 3] = (HALF)(e << 1 | (s > 0));
+		A[m1 - 3] = ((HALF)(e << 1) | (HALF)(s > 0));
 		A[m1 - 4] = u;
 		A[m1 - 5] = (HALF)(f >> BASEB);
 		A[m1 - 6] = (HALF)f;
@@ -1585,7 +1585,7 @@ zsqrt(ZVALUE z, ZVALUE *dest, long rnd)
 				if (x & TOPHALF)
 					a[1] |= 1;
 			}
-			*a = (HALF)((x << 1) | (u > 0));
+			*a = ((HALF)(x << 1) | (HALF)(u > 0));
 		}
 		else
 			*a = u;
diff --git a/zprime.c b/zprime.c
index 7a783c2..926c2ff 100644
--- a/zprime.c
+++ b/zprime.c
@@ -778,8 +778,8 @@ small_factor(ZVALUE z, FULL limit)
 #if BASEB == 32
 		div.v[0] = (HALF)factor;
 #else
-		div.v[0] = (factor & BASE1);
-		div.v[1] = (factor >> BASEB);
+		div.v[0] = (HALF)(factor & BASE1);
+		div.v[1] = (HALF)(factor >> BASEB);
 #endif
 
 		if (zdivides(z, div))
@@ -1483,8 +1483,8 @@ zlowfactor(ZVALUE z, long count)
 #if BASEB == 32
 		div.v[0] = (HALF)factor;
 #else
-		div.v[0] = (factor & BASE1);
-		div.v[1] = (factor >> BASEB);
+		div.v[0] = (HALF)(factor & BASE1);
+		div.v[1] = (HALF)(factor >> BASEB);
 #endif
 
 		if (zdivides(z, div))
diff --git a/zrandom.c b/zrandom.c
index c401b44..50a4584 100644
--- a/zrandom.c
+++ b/zrandom.c
@@ -1733,7 +1733,7 @@ zsrandom2(CONST ZVALUE seed, CONST ZVALUE newn)
 			math_error("srandom newn == 0 reserved for future use");
 			/*NOTREACHED*/
 		}
-		set = z1tol(newn);
+		set = (HALF)z1tol(newn);
 		if (!zistiny(newn) || set > BLUM_PREGEN) {
 			math_error("srandom small newn must be [1,20]");
 			/*NOTREACHED*/